Electrical plug and socket assembly



P" 1956 c, H. STEVENS, JR

ELECTRICAL PLUG AND SOCKET ASSEMBLY Filed July 8, 1953 INVENTOR Charles H. Stevens, Jr.

BY 7 1 W uvv ATTORNEYS United SratesPatent 2,742,624 ELECTRICAL PLUG AND SOCKET ASSEMBLY Charles H. Stevens, Jr., Cornwall Bridge, Conn., assignor, by mesne assignments, to Whitney Blake Company, New Haven, Conn., a corporation of Connecticut Application July s, 1953, Serial No. 366,729 v 3 Claims. (Cl. 339-125 The present invention relates to improvements in electrical connectors and more particularly to improved plug and socket elements. My copending application Ser. No. 241,608, filed August 13, 1951, now Patent No. 2,677,115 dated April 27, 1954, relates to similar general subject matter.

The problems arising relative to theme of wires or cables and connectors especially on shipboard or in shipyards has been discussed in the aforesaid application. The present invention has for its object to provide improved socket and plug elements wherein the structure thereof provides additional safety and efficiency in use.

A more specific object of the present invention is to provide improvements in the socket and mounting means therefor and the relationship therebetween whereby the socket can be mounted on a vertical wall, suchas in a main outlet box, and the plug receiving face will-be inclined so as to face downwardly for visual observation of the location of the pin receiving sockets or bores to facilitate insertion of the pins of the plug member.

An additional object of the present invention is to so form the molded body of the socket that precipitation will run off the same without tending to seep into or collect in the pin-receiving sockets or bores.

A still further object of the present invention is to provide an improved plug and socket assembly wherein in etfecting connection, a ground connection is initially made, a complete seal around the other contact pins is secondarily made, and electrical contact between said other contact pins and the respective sockets therefor is tertiarily made.

Various other objects and advantages will become apparent from the detailed description to follow.

In the drawings:

Fig. 1 is a perspective View of the plug and socket assembly;

Fig. 2 is a vertical longitudinal sectional view through the assembly of Fig. 1; I

Fig. 3 is a view similar to Fig. 2 but showing the contact elements in full lines rather than in section and showing the plug member in separated relationship to. the socket and also showing in dotted lines the coaction between the plug and socket as the plug is grounded to'the socket;

Fig. 4 is a transverse sectional viewtaken along the plane of line 4-4 of Fig. 2;

Fig. 5 is a view of the plug as seen from the bottom, parts being in section;

Fig. 6 is a front elevational view of the socket; and

Fig. 7 is a rear elevational view of the socket.

Referring more particularly to the drawings. wherein like numerals designate like parts, it will be seen that a plug and socket assembly designated generally by the numeral 10 has been provided and is comprised of an electrical socket 12 and plug 14 removable therefrom.

The socket 12 as shown in Figs. 2, 3, 6 and 7 is com prised of a generally cylindrical body 16 of molded neopending application.

prene or other suitable insulative material stable over substantial changes in temperature, dense and yet capable of'absorbing the shock of a blow such as may occasionally accidentally occur to such an assembly. The body 16 includes opposing end faces 18 and 20 and an attachme t plate 22 unitarily extends from said body intermediate said end faces and has its plane at an angle less than relative to the axis of the body. Embedded in the attachment plate 22 is a rigidifying annular element 24. Through the plate and rigidifying element 24 several holes are bored as at 26 in Figs. 1 and 6, for the passage of attachment bolts.

I Within the cylindrical body 16 several contacts 28, 30, 32 and 34 are embedded, common ends thereof being flush with the end face 18 and each having a threaded bore therein at that end for threadedly receiving'the screws36, 38, 40 and 42 therein. The latter screws are employed for securement of conductors or wires such as may be found in the interior of a main outlet connector box. The contact elements 28-34 are formed from elongated rod-like pieces of brass but may be of other suitable electrically conductive material. Contact elements 28-32 are identical in that the lengths of each are the same as the others and also less than the length of the body 18. The end portions of the contact elements 283 2 terminating within the body, rather than at the face 20, have socket-like bores formed therein as at 42 in Fig. 2. Between theend portion of each of the contacts 28-32 and the face 20 of the body, a bore is formed, the wall portions of which reversely taper as at 44, 46 inFig; 3 in the manner as disclosed in my aforementioned co- The Contact element 34 extends for the full'length of the body and terminates at the face 20 in the flared lip portion at 48, a bore 50 extending inwardly from the lip portion and providing a pin-receiving socket for grounding the plug. I

All of the Contact elements 28-34 are similarly formed withlongitudinally extending slits as at 5'2 and 54in Fig. 3 which slits extend from the pin-receiving end of the contact elements so as to impart resiliency thereto for permitting insertion of the pins of the plug thereinto while providing tight electrical contact.

3642 so as to prevent arcing therebetween.

The plug 14 has its details best shown in Figs. 2-5 and is formed in a manner similar to that of the socket, that is, the plug body 66 is molded of neoprene or other insulative material with all of the component elements thereof "embedded therein during molding. The cable 68, which includes four conductors 70 to handle 3-phase power and a ground conductor 72, is similarly encased in neoprene and molded unitarily with the body 66. The body 66 terminates in the end face 74 from which the contact elements, fingers or pins 76, 78, 80 and 82 extend. The B-phase conductors 70 each have their wire ends connected with one of the pins 76, 78 and 80 as at 84 in Fig. 2, while the ground wire is connected with its respective pin at 86. The exterior surfaces of all of the pins 7682 to the extent that they are embedded in neoprene are roughened as with knurling at 88, 90. A rigidifying and spacer element 92 of hard rubber or the like and provided with four predeterminately spaced openings 94, 96, 98 and 100 therethrough receives the four pins therethrough prior to molding.

The pins 76, 78 and 80 for the 3-phase power have jacket-s 102, 104 and 106 around knureld portions thereof,

the jackets each having reversely tapering surfaces at 108 and 110, as in my referred to copending case, for cooperation with the corresponding Wall surfaces at 44 and 46 in the socket body.

.The exposed length of each of the pins 76, 78 and 80 is less than the distance between the ends of the contact elements 28, 30 and 32 and the adjacent face 20 as shown by the dotted line position of the plug cooperating with the socket. Furthermore, the relation between the contact pins 7680 and the pin 82 is such that when the pins 76-82 are inserted into the respective bores of the socket, the pin 82 contacts the ground contact element 34 even before the jackets 102, 104 and 106 sealingly engage the end face 20.

From the foregoing, it will be seen that the socket 12 for the various requirements in shipyards or on board ship, the plug is moved in the manner shown in Fig. 3

.from the full line position to the dotted line position at -which point the ground pin 82 is grounded to the end 48 of the contact 34, and the jackets 102, 104 and 106 will be sealingly contacted with the end face 20 of the socket.

Further axial movement engages the ground pin into the socket 50 of the contact element 34 and the three pins 76,

78 and 80 into the sockets of their respective contact elements, while the jackets are firmly engaged in the cooperating complimentary bores outwardly of the sockets. The connection is now tightly made and is completely sealed from the atmosphere. Furthermore, because of the jacket and complementary bore arrangement, separation of the plug from the socket cannot unintentionally be made for astrong force is required for the separation.

When separating the plug from the socket, the reverse of the above occurs, the ground connection being the last-to be broken.

It is to be noted that the cross-section of the plug, Fig.

.4, and also shown by Fig. 1, is such as to indicate that the :plug is for 3-phase connection, that is, the plug essentially is formed as three ribs 112, 114 and 116.

As this invention may be embodied in several forms .without departing from the spirit or essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is i defined-by the appended claims rather than by the description preceding them, and all changes that fall within the metes and bounds of the claims or that form their func tional. as well as conjointly cooperative equivalents, are therefore intcnded to be embraced by those claims.

I claim: 1. An electrical outlet socket, comprising an elongate body of resilient insulation material,v an attachment plate disposed between the ends of the body and lying in a vplane extending across and oblique to the length of the body, said plate being constructed to be secured against a wall of an outlet box and embodyingan integral extension of the insulation material of the body and a relatively rigid metal stiffening element completely encased in the extension of the insulation material, electrical contact ele ments embedded in and extending longitudinally ofthe body and having corresponding ends exposed at one end of the body, one of said elements having its opposite end exposed at the other end of the body .andthe remaining elements each terminating short of the said other end of the body and at the inner end of a socket formed in the insulation material of the body and opening through said other end thereof. I

2. An electrical outlet socket comprising an insulative body having a plate encircling the body obliquely with respect thereto and constructed for attachment to an outlet box to mount the body thereon, electrical contact means in said body each .with one end at one side of said plate for connection with a power source and ground respectively, and with vthe opposing end at the other side of said plate for electrical connection with a plug having a ground contact, said body and attachment plate being unitarily molded and including a rigidifying insert embedded in said plate in encircling relation with the body and projecting. partially into said body.

3. In an electrical outlet socket and plug combination, a socket comprising an elongate body'of resilient insulation material, an attachment plate disposed between the ends of the body and lying in a plane extending across and oblique. to the length of the body, said plate being constructed to besecured against a wall of an outlet box and embodying aan integral extension of the insulation material of the body and a relatively rigid metal stiffening element completely encased. in the extension of the insulation material, electrical contact elements embedded in and extending longitudinally of the body and having corresponding ends exposed at one end of the body, one of. said elements having its opposite end exposed" at the other end of the body and the remaining elements each 'terminatingshort .of the said other end of the body at and exposed in the inner end of a socket formed in the insulation material-of the body and opening through said other end thereofythe exposed endof said one of the elements being provided with a bore, and a plug including a body -of insulation material, a ground contact pin and, other electricalcurrent conducting pins extending in substantially parallel relationship from the plug body, the ground contact extending into the bore of the said one element and the other electrical current conducting pins extending into said sockets. for electrical connection with the remaining contact elements exposed therein, means on said other current conducting pins for sealing the sockets upon introduction of the pins into the sockets and before the pins electrically contact the said other contact elements, said ground contact pin being of a length relative .to the other pins such that it will make electrical connection with-said ground contact before the other pins make electrical connection, with said other contact ele- -ments.

References Cited-in the file of this patent UNITED STATES PATENTS 1,672,067 vra siregn, June '5, 1928 1,981,460 Miller; "Nov. 20, 1934 2,077,686 .Gober Apr. 20,1937 2,204,948 Pond"; June 18, 1940 2,275,762 Horton "Mar. 10, 1-942 2,294,880 Alden; Sept. 8, 1942 2,364,194 f C,ortner Dec. 5, 1944 I 2,396,872 Miller et, a1 Mar. 19, 1946 2,409,004, 'Wall "Oct. 8, 1946 2,411,861" Antony, Jr., et al Dec. 3, 1946 2,429,955 Goldsmith "Oct. 28, 1947 2,438,572 McCorma'ck Mar. 30, 1948 2,619,515 Doane Nov.25, 1952 2,633,483 Hafke a a ,Mar. 31, ,1953 2,677,115 Stevens Apr. 27, 1954 FOREIGN PATENTS Great Britain .Jan. 28, 1949 

